This invention relates to improvements in fans and relates particularly to improvements in axial fans wherein a plurality of fan blades extend radially from a hub.
Fans are commonly formed of synthetic plastics material by injection moulding. An injection moulding tool is made which defines the shape configuration and structural features of the moulded fan. However, the cost of injection moulding tools is extremely high and a different tool is required for fans of different shapes, sizes, blade pitch angles, number of blades, hub structures and shapes and the like.
While it is known to manufacture fans using an assembly process where individual blades are attached to a hub by a fastener or the like, such processes are relatively expensive due to the handling and assembly time.
It is therefore desirable to provide an improved fan structure which obviates at least some of the disadvantages of the existing fans.
It is also desirable to provide an improved method of manufacturing a fan which obviates disadvantages of existing manufacturing methods.
It is also desirable to provide an improved method of manufacturing a fan which facilitates varying the fan characteristics.
It is also desirable to provide an improved fan manufacturing process which is relatively simple and is economical.
It is also desirable to provide an improved fan manufacturing method which produces a single piece fan.
It is also desirable to provide a method of manufacturing fans of different sizes, configurations and with different properties using standard components.